Sewing machine lubricating means



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B c. ELLERSICK 2,302,606

SEWING MACBINE LUBRICATING MEANS Fild Jan; 16, 1941 jiii r t BernardEllersick Ltimes.

Patented Nov. 17, 1942 SEWING MACHINE LUBRICATIN G MEANS Bernard C.Ellersick, St. Louis, Mo., assignor to The Singer Manufacturing Company,Elizabeth, o N. J., a corporation of New Jersey 1.

Application January 16, 1941, Serial No. 374,615

3 Claims.

This invention relates to sewing machines and famore particularly tomeans for lubricating the mechanism within the hollow head.

, When sewing machines of the lock-stitch type are operated at highspeeds of about 80 revolutions a second, lubrication of the bearingsurfaces of the crank for the needle-bar and takeup links is difficult.Due to the high speed, if oil is supplied from a point exteriorly of thehearing the centrifugal force created by the high speed throws the oiloff before it reaches the bearing surfaces. On the other hand, if oil issupplied through the crank to the bearing surface, it is di'flicult tometer the oil with the result that either not enough or too much oil issupplied at the various speeds.

Oiling the mechanism of sewing machines presents many problems for themachine may be called upon to operate at 100 R. P. M. for a few seconds,then jumped to 5000 R. P. M. and in finishing the seam the speed may bereduced to 500 R. P. M. On other work the same machine may beaccelerated from to 5000 R. P. M. in less than a second, and on heavywork the machine may not be operated over 2000 R. P. M. at any time.Under these varying conditions the correct amount of oil must besupplied at all Insufiicient oil will, of course, cause rapididisintegration of the parts and an oversupply will .damage the work. Itis the object of this in- .7 vention to deliver a small quantity of oildirectly 0 the bearing surface of the crank within the hollow head eachtime the crank is rotated, thereby applying a film of oil directly tothe crank and eliminating the uncertainty of the oil not reaching thebearing surface.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations, and arrangements ofparts hereinafter set forth and illustrated in the accompanying drawingof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

Figure l is a front elevation of the hollow head of a sewing machineembodying my invention, the face-plate being removed to disclose theparts within the head.

Figure 2 is an enlarged detailed view of the crank and link connectionswithin the hollow head.

Figure 3 is a side elevation and Figure 4 is a section of the operativeconnection between the needle-bar link and the crank.

Figure 5 is a view similar to Figure 4, showing a construction in whichthe crank-pin is directly wiped by the wick.

In the embodiment of this invention selected for illustration, l0represents the usual hollow head in which is journaled a rotaryactuating shaft H, and fixed to the end extending into the hollow headis a crank-disk I2 carrying the crank-pin [3 which actuates the link Hof the needle-thread take-up mechanism l5. Carried by the crank-pin I3is a second crank-pin l6 which is embraced by the strap 18 at one end ofa pitman H, the other end of the pitman being operatively connected tothe needle-bar l9 which is journaled in the bearings 20 and carries aneye-pointed needle 2|. Interposed between each of the crank-pins l3 andI6 and the strap l8 of the pitman I1 and the strap H of the link 14 area series of small rollers or needle-bearings 22 which serve to reducefriction between these elements and the crank-pins. bearings 23 in thehollow head is the usual presser-bar 24 which is constantly urgeddownwardly by the spring 25. To the lower end of the presser-bar 24 theris secured the usual presser-foot 26 which cooperates with the feeddog(not shown) for advancing the material. Fixed in the upper part of thehead of the machine is a supporting plate 21 provided with dependingtubes 28 which carry wicks 29, the function of which will be hereinafterdescribed. For a complete description of the sewing machine, and theparts above described, reference may be had to the patent to R. Kaier,No. 2,206,285, dated July 2, 1940.

To adequately lubricate the bearing surface between the rollers 22 andthe strap I8 of the pitman I1, I have provided the strap I8 with anelongated peripheral opening 30 which extends through the upper portionof the strap of the pitman so as to expose the rollers 22 (Figs. 3 and4). As shown, the wicking 29 is bent back upon itself in the tube 28 toform a loop and this loop extends downwardly to a point so that it willengage the rollers 22 on each rotation of the crank. A thin film oflubricant is thus applied directly to the bearing surface and it findsits way underneath the strap before it is thrown off by the centrifugalforce created by the operation of the parts It will be understood thatthe wicks are constantly supplied with lubricant during the operation ofthe machine, the same means being used as that shown in the Kaier patentreferred to above. 7

It will be observed that the portion of the J ournaled in strap [8 inwhich the opening is located is thickened to add strength to'the tworibs [8' which are located on each side of the opening (Figs. 3 and 4)It will also be understood that the bearing surface between the strap l4of'the link [4 and the crank I3 is lubricated in the same way as thatused for lubricating the strap l8. The rollers 22 which are interposedbetween the crank-pins l3, l8 andthe straps I4 and I8 are for thepurpose of reducing friction and, so far as this invention is concerned,the rollers 22 may be considered as part of the crank-pins which theyencase.

Having thus set forth the nature of the invention, what I claim hereinis:

1. In a sewing machine having an endwise reciprocatory needle, a rotarycrank-shaft, an antifriction bearing on the crank of said shaft, :2.needle-driving connecting rod having a strap embracing said antifrictionbearing, the improvement which consists of the provision of a periph- Ierally elongated opening in the strap of said conby said antifrictionbearing through the peripherally elongated opening in said connectingrod strap.

2. In a sewing machine having a. hollow head, a rotary crank within saidhead, a link having a strap at one end which embraces said crank, theother end of the link being connected to one of the elements of thestitch-forming mechanism, said strap having a peripherally elongatedgroove which extends therethrough, a stationary wick holder dependingfrom the top of the hollow head, and a wick threaded into said holder sothat it depends therefrom in a loop which enters said groove and engagessaid crank.

3. In a sewing machine having a hollow head, a rotary crank within saidhead, the crank being embraced by the crank-strap of a crank drivenelement and having a bearing surface therebetween, the improvement whichconsists in the provision of a stationary lubricant conducting wickarranged to be wiped by said bearing surface and the provision of anopening in said strap large enough to expose a portion of said bearingsurface to the wiping action of said wicl'u BERNARD c. ELLERSICK.

